It doesn't matter, if she's working for Santa Monica she is contributing. Game developers play each others games all the time, this is a non-issue being created by dumbfucks.
Agreed, it would be even more weird if Sony was telling its developers to never play any games outside of Sony games.
They want their developers to be inspired and see what others are doing, so I doubt Sony would ever really care, its like people are trying their best to make it an issue, but Sony has never treated employees with this "ONLY PLAY PS" idea.
I'd argue none of the publishers really do anything odd like that.